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Re: Noise reduction

Subject: Re: Noise reduction
From: "Bernie Krause" bigchirp1
Date: Sun Mar 1, 2009 11:04 am ((PST))
I hear that there's a version of that system over at Lawrence Hall of
Science in Berkeley, Rob. As I understand it, wax cylinders, old 78s
and even 45s and 33s are now scanned that way...which is just amazing
to old farts like me who used to listen to the first 78s of blues and
jazz of the 20s by Leadbelly and Armstrong. I still have a few rare
unreleased versions lying around, but nothing to play them on.
Compared to the wax versions, these clean up pretty nicely with not
much artifact.

Early wax cylinders of a certain type initially were made from 8.5 x
11 pieces of paper onto which one side was injected a layer of
hardened wax. The paper was then curled, overlapped and joined at the
seam and made into a kind of roll that was then mounted onto a
rotating drum. The drum rotated 240 x per second (Edison version). The
horn, into which voice or instruments were performed, was attached to
a diaphragm onto which a needle was mounted. When the diaphragm was
excited it transferred the vibrations onto wax. Thus sound (albeit
with 240 clicks a minute as the playback needle moved past the seam
during each rotation). There was another problem, though. Wax
cylinders of this nature were often stored wrapped in cotton. The
bacteria in the cotton ate away at the wax, which had a biological
base. Thus the terrible quality of those early recordings. BTW, myth
has it that one of the first Edison recordings was that of an American
Robin, that landed close to the horn of one of his devices in his
backyard. I've got rare recordings in my archive, but that one I'd
kill for.

Bernie

On Mar 1, 2009, at 8:54 AM, Rob Danielson wrote:

> Hi Bernie--
> Interesting project. I bet it would be very expensive to explore the
> "no-needle" scan methods. Its been a couple of years since this
> (pdf) report: http://tinyurl.com/b4ulam but I've heard a related
> process is now quite effective with optical sound on paper. Makes
> sense to suppress the mechanical weaknesses/patterns working from
> digital scans and avoid recreating them with needle playback. Then
> you can go after it with developments in audio signal noise
> reduction! :-) Rob D.
>
> =3D =3D =3D
>
> At 7:01 AM -0800 3/1/09, Bernie Krause wrote:
> >In the old transitional days, when analog tape was still the
> >preference, and adaptive-predictive-deconvolution systems first
> >emerged (digital systems in the early 80s) you could really hear the
> >artifacts, and the result was unimpressive when compared to the cost.
> >And I agree, to some extent the artifacts are still present. But when
> >trying to distinguish detail inherent in language from whatever
> >source, human or non-human, and where subtleties are important in
> >decryption - especially with extremes like old wax cylinders - this
> is
> >just another tool. The example I showed was where the noise was gone.
> >Different levels of noise reduction left more of the original context
> >intact.
> >
> >For the linguistic anthropologists at the Lowie Museum in Berkeley,
> >where the Ishi archive is stored, and where the focus is on content
> >and language recovery rather than audio fidelity, this type of
> >approach means a great deal. If more than very subtly applied, it
> >would certainly destroy all of the spatial imaging of an otherwise
> >well-recorded stereo or MS recording not to mention the inherent
> >details of the biophony.
> >
> >Noise deconvolution has a way to go but it's coming along in pretty
> >amazing ways. Eventually, it may even work for continuously variable
> >noise like the Doppler shift and audio levels of a jet flying
> overhead
> >ruining an otherwise perfect natural audio clip.
> >
> >Bernie
> >
> >On Feb 28, 2009, at 11:13 PM, Dan Dugan wrote:
> >
> >> Bernie, you wrote,
> >>
> >> > The audio clip contains a 30 second example of the original
> >> > wax cylinder recording followed by the same clip cleaned up.
> >> > Considering the quality of the original very few artifacts remain
> >> when
> >> > compared with other options.
> >>
> >> But all the naturalness is gone too, replaced by a strange robot-
> like
> >> quality. I've done quite a bit of noise reduction work, and I often
> >> hate myself in the morning. I get tuned into the noise, and it
> seems
> >> great to get rid of it, but later I realize that the cost was too
> >> great.
> >>
> >> -Dan Dugan
> >>
> >>
> >
> >Wild Sanctuary
> >POB 536
> >Glen Ellen, CA 95442
> >707-996-6677
> ><http://www.wildsanctuary.com>http://www.wildsanctuary.com
> ><chirp%40wildsanctuary.com>
> >Google Earth zooms:
> ><http://earth.wildsanctuary.com>http://earth.wildsanctuary.com
> >SKYPE: biophony
> >
> >
> >
> >
>
> --
>
>
>
>

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707-996-6677
http://www.wildsanctuary.com

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